18 research outputs found
DNA damage in a human population affected by chronic psychogenic stress
The effects of chronic psychogenic stress on the expression of DNA
damage and cellular response to the damage were investigated. Using the
comet assay, basal DNA damage was found to be similar in lymphocytes of
both affected and non-affected Populations (n = 30 in both groups). The
induction of DNA damage in lymphocytes by external factors (H2O2 and
gamma-irradiation), was also investigated. In these Studies, cells were
treated with 50, 100 and 150 muM H2O2 for 5 minutes or with 0.8, 2.5 and
4.2 Gy gamma-rays. A significant difference was found between the
chronically stressed and the control populations, indicating the
enhanced sensitivity of the former population. Cells were also held for
2 hours after the treatment, allowing time for the cells to deal with
the induced DNA damage. Based on the level of residual DNA strand
breaks, cells from the stressed population had more breaks than the
controls. Gender does not alter these findings. In conclusion, our data
indicate that cells from the stressed population were more sensitive to
the induction of DNA damage and had higher level of residual damage.
Therefore, stress conditions may cause the affected individuals to be
susceptible to environmental mutagenic agents
DNA damage and repair efficiency in lymphocytes from schizophrenic patients
In the present study we examined schizophrenic patients’ lymphocytes
sensitivity to the effects of external factors, such as hydrogen
peroxide and gamma-irradiation and also their repair efficiency with the
comet assay. Our results did no show any difference in basal levels of
DNA damage between schizophrenic and normal populations. The slightly
increased sensitivity of the schizophrenic population to the externally
induced DNA damage compared to controls was not statistically
significant. Also the small reduction in the DNA repair efficiency in
schizophrenics in comparison to normal population was found to be not
statistically significant. Finally, patients with heritable
predisposition to schizophrenia did not show any difference in their
response from the other schizophrenics. (C) 2003 Elsevier Ireland Ltd.
All rights reserved
Effects of pulsed electric fields on DNA of human lymphocytes
The effects of pulsed electric fields of low frequency (50 Hz) on DNA of human lymphocytes were investigated. The influence of additional external factors, such as hydrogen peroxide (H2O2) and gamma-irradiation, as well as the repair efficiency in these lymphocytes, was also evaluated. The comet assay, a very sensitive and rapid method for detecting DNA damage at the single cells level was the method used. A significant amount of damage was observed after exposure to the electric fields, compared to the controls. After 2 h incubation at 37 degrees C, a proportion of damage was repaired. H2O2 and gamma-irradiation increased the damage to lymphocytes exposed to pulsed electric fields according to the dose used, while the amount of the repair was proportional to the damage
The use of comet assay in measuring DNA damage and repair efficiency in child, adult, and old age populations
In the present study, we used the Comet assay to estimate basal DNA damage in three distinct populations aged 5-10, 40-50, and 60-70 years old. The DNA damage induced by hydrogen peroxide and gamma-irradiation in the lymphocytes of these populations, as well as their repair activity, was also studied. Finally, we measured apoptosis and necrosis after the effect of these agents. Our results indicate that the older population (60-70 years old) showed higher basal levels of DNA damage and was more sensitive to the effects of the DNA-damaging agents than the adult one (40-50 years old), who, in turn, was more sensitive than the younger population (5-10 years old). A decline of the repair efficiency with age to the DNA damage induced by the two agents was also observed. Apoptosis and necrosis were also affected by age